Apparatus for the gaseous reaction of material

ABSTRACT

Apparatus comprising a vessel, means for compacting material and supplying the compacted material to the vessel, means for breaking-up the compacted material and spreading the broken-up material in the vessel, means for supplying gas to the vessel, and discharge means for discharging material in compacted condition, such discharge means including a discharge opening and flap means causing material to be discharged therethrough in said compacted condition. A rotatably driven platform divides the vessel into communicating retention and discharge chambers and controls the passage of material from the retention chamber to the discharge chamber; and the retention chamber is connected to the material and gas supplying means and contains the material breaking-up and spreading means, while the discharge chamber is provided with a large, offset, discharge opening and contains a scraper movable thereover.

United States Patent [1 1 Carlsmith et a1.

APPARATUS FOR THE GASEOUS REACTION OF MATERIAL Inventors: Lawrence A. Carlsmith, Amherst,

N.l-l.; William L. Mallory, Beaconsfield, Quebec, Canada; Joseph K. Perkins, Nashua, NH.

[451 Jan. 15, 1974 Primary Examiner-Granville Y. Custer, Jr. Attorney Robert R Paquin and David W. Tibbott [5 7] ABSTRACT Apparatus comprising a vessel, means for compacting material and supplying the compacted material. to the vessel, means for breaking-up the compacted material and spreading-the broken-up material in the vessel, means for supplying gas to the vessel, and discharge means for discharging material in compacted condition, such discharge means including a discharge opening and flap means causing material to be discharged therethrough in said compacted condition. A rotatably driven platform divides the vessel into communicating retention and discharge chambers and controls the passage of material from the retention chamber to the discharge chamber; and the retention chamber is connected to the material and gas supplying means and contains the material breaking-up and spreading means, while the discharge chamber is provided with a large, offset, discharge opening and contains a scraper movable thereover.

20 Claims, 3 Drawing Figures PAIENTEDJAN 1 5mm SHEH 1 0F 2 1 APPARATUS FOR THE GASEOUS REACTION OF MATERIAL The present invention relates to apparatus for the gaseous reaction of material such as a solid or solidliquid mixture.

Conventional apparatus employed for continuous operation in the gaseous reaction of lignocellulosic material, such as the bleaching of pulp or the delignification of lignocellulosic material, is inherently subject to undesirable carryover of the gaseous reagent in the discharged material. This carry-over not only results in undesirable loss of the gaseous reagent, but also causes problems in the handling of the discharged material and, or course, results in increased operating costs.

An object of the present invention is to provide new and improved apparatus for the gaseous reaction of material such as a solid or solid-liquid mixture, which apparatus is particularly constructed and arranged to substantially minimize the carry-over of the gaseous reagent with the discharged material.

Another object of the invention is to provide new and improved apparatus for the gaseous reaction of material such as a solid or solid-liquid mixture, which apparatus is particularly constructed and arranged to discharge material at high consistency.

Another object is to provide new and improved gaseous reaction apparatus particularlyconstructed and arranged to both receive and discharge material at high consistency.

Another object is to provide new and improved apparatus of the type set forth which, although particularly suited for employment in a pulp bleaching or delignification process, is alternatively capable of use in the gaseous reaction of other solid-liquid and solid material.

Other objects and advantagesof the invention will be apparent from the following description taken in connection with the accompanying drawings wherein, as will be understood, the preferred embodiment of the invention has been given by wayof illustration only.

In accordance with the invention, an apparatus for the gaseous reaction of material, may comprise a vessel, means for supplying material to said vessel, said material supplying means including means for compacting material and supplying the material in compacted condition, means for breaking-up the compacted material and spreading the broken-up material in the vessel, means for supplying gas to the vessel, and discharge means for discharging material from the vessel, the discharge means including a discharge opening and flap means controlling the discharge of material through the discharge opening for causing the material to be discharged therethrough in compacted condition. Also, in accordance with the invention, the apparatus may comprise dividing means dividing the vessel into communicating retention and discharge chambers and controlling the passage of material from the retention chamber to the discharge chamber; and the retention chamber may be connected to the material and gas supplying means and contain the material breaking-up and spreading means, while the discharge chamber may be provided with a large, offset discharge opening and contain a scraper movable thereover,

' Referring to the drawings:

FIG. 1 is an elevational view, partially broken away and in section, of an apparatus constructed in accordance with the present invention;

FIG. 2 is a sectional view taken on line 22 in FIG. 1, looking in the direction of the arrows; and

FIG. 3 is a sectional view taken on line 3-3 in FIG. 2, looking in the direction of the arrows.

Referring more particularly to the drawings wherein similar reference numerals designate corresponding parts throughout the several views, the illustrated apparatus comprises a generally vertical, annular vessel 10 which is closed at its upper and lower ends by end closure plates 12, 14, respectively, and ground mounted by supporting pillars or piersil6. The vessel 10, asdesired or required by the gaseous reaction process to be carried out by the apparatus, may be designed for operation at atmospheric pressure or at any other pressure above or below atmospheric pressure; however, in any event the vessel 10 is gas tight to prevent gas leakage into and out of the vessel 10.

' The vessel 10 is provided with a gas inlet or inlet conduit 18 which connects the upper end of the vessel interior to a gas supply pipe 20, in turn, communicating with a source (not shown) of the gas or gaseous reagent to be employed duringoperation of the apparatus. The

employed gaseous reagent will, of course, depend upon the gaseous reaction process to be performed; and, by way of specific example only, either chlorine gas or chlorine dioxide mixed with steam could be used as the gaseous reagent when the apparatus is employed for the bleaching of pulp. The vessel 10 is also provided with means adapted for compacting material to be reacted with the gas and feeding or supplying the compacted material to the vessel 10, whereby the compacted material forms a plug upstream of the vessel 10 to prevent air and other undesirable gases from being introduced into the vessel 10 with the material.

More particularly, as illustrated, the vessel 10 is provided with a material inlet or inlet conduit 22 which is connected to the upper end of the vessel interior centrally of the vessel 10. The inlet conduit 22 contains a feed screw 24-, mounted on a supporting shaft 26 rotatably driven by a driving motor 28, which is adapted for downwardly feeding the material into the vessel interior. The inlet conduit 22 is connected through a supply conduit 30 to a source (not shown) of the material, the supply conduit 30 including a portion 32 tapering in cross-section in the. direction of the passage of material to the vessel 10 therethrough. A rotatably driven shaft 34 is coaxially disposed in the supply conduit 30 and in the tapering portion 32 thereof carries a feed and compaction screw 36. Hence, during operation of the apparatus, the driven rotation of the feed and compaction screw 36 in the tapering portion 32 of the supply conduit 30 causes compaction of the material in the supply conduit 30 to prevent the flow of. undesirable gases therethrough, while the feed screws 24, 36 feed the material to the vessel upper end.

The upper end of the vessel 10 contains means particularly adapted for disintegrating or breaking-up the compacted material supplied through the inlet conduit 22 and spreading the disintegrated or broken-up material across the cross-section of the vessel 10. As illus trated, this disintegrating and spreading means comprises an inner annulus or ring of arcuately spaced apart rotary pins 38 and a concentric, radially spaced, outer annulus or ring of arcuately spaced apart stationary pins 40. The upper ends of the stationary pins 40 are rigidly mounted on an annular support 42 which is affixed around the wall of the inlet conduit 22; the lower ends of the stationary pins 40 are affixed to a stationary support 44 which surrounds supports the lower end of the shaft 26. The rotary pins 38 are carried by a frame 46 which is mounted on the shaft 26 for rotation therewith, the frame 46 including upper and lower plates 48,50, respectively, rigidly connected to the corresponding ends of the rotary pins 38. The upper frame plate 48, as will be noted, is spaced from the shaft 26 by an at least generally annular space 52, whereby the space 52 communicates the inlet conduit 22 with the chamber 54 within the annulus of rotary pins 38. Hence, during the operation of this disintegrating and spreading means, the rotary pins 38 are continuously rotatably driven by rotation of the shaft 26 and the material supplied to the chamber 54 through the space 52, being prevented from direct downward passage in the vessel by the plate 50 and support 44, is disintegrated by the pins and passes outwardly through the spaces between adjacent ones of the pins to be resultantly spread in disintegrated or broken-up condition across the cross-section of the vessel 10. However, it will be understood that this illustrated material disintegrating and spreading means, and also the beforedescribed material compacting and supplying means, have been shown as being of described construction only for the purposes of illustration, and alternatively could be of other construction suitable to perform their intended functions.

The lower end of the vessel 10 is provided with discharge means particularly constructed and arranged to cause material to be discharged from the apparatus in compacted condition. As illustrated, the lower end portion of the vessel 10 is enlarged and the vessel bottom 56 is constructed of generally conical configuration. Offset from the center or vertical axis of the vessel 10, the vessel bottom 56 is provided with an elongated discharge opening 58 which longitudinally extends substantially across the vessel 10 at its offset location. The lower end of the vessel 10 contains a coaxial, rotatable scraper 60 having a plurality of scraper arms or blades 62, each of sufficient length to move or sweep over the discharge opening 58; and the scraper 60 is mounted on a rotatable shaft 64 which is rotatably driven by a driving motor 66. 7

An elongated, horizontal, discharge conduit or conduit means 68 longitudinally extends transversely or cross-wise of the vessel 10 at the offset location of the discharge opening 58 parallel to and beneath the latter, and projects outwardly from the vessel 10. As shown in FIG. 2, the discharge conduit 68 extends beneath the full length of the discharge opening 58; and the discharge opening 58 is open throughout its length to the therebelow discharge conduit 68. The discharge conduit 68 contains a coaxial, rotatable shaft or support 70, which extends the full length of the discharge conduit 68 and is connected to a driving motor 72 to be rotatably driven thereby. The shaft 70 includes an enlarged portion 74 which cooperates with a thereadjacent portion of the wall of the discharge conduit 68 to bound a therebetween annular discharge opening 76 communicating through the discharge conduit 68 with the discharge opening 58. The portion of the shaft 70 intermediate the discharge openings 58, 76 carries a screw flight 78 which, during the driven rotation of the shaft 70, serves to convey material through the discharge conduit 68 from adjacent the discharge opening 58 towards the discharge opening 76.

Annular flap means control the discharge of material through the discharge opening 76 to cause the material to be discharged therethrough in compacted condition, such flap means movably extending generally transversely of the discharge opening 76 and being caused to yieldably restrain discharge of material through the latter. More particularly, as illustrated the flap means comprises an annulus or ring formed from a plurality of imperforate, rigid flaps 80, cooperative to encircle the enlarged shaft portion 74 and each extending generally transversely of the discharge opening 76, which are pivotally mounted by individual pivotal mountings 82 on a support plate 83 carried by the wall of the discharge conduit 68 to be individually movable towards-andaway from the enlarged shaft portion 74 for yieldably restraining discharge of material through the discharge opening 76. The flaps are, as shown in FIGS. 2 and 3, connected by individual links 85 to individual pressure fluid operated actuators 84, per se of any suitable conventional construction, which during the operation of the apparatus are fluid caused to bias their respective flaps 80 towards the enlarged shaft portion 74 and against the discharge of material through the opening 76 to thereby cause the flaps 80 to yieldably restrain material passage through the opening 76. As illustrated, the flaps 80 are eight in number, it being understood, however, that alternatively they could be of other desired number.

On the opposite side of the discharge opening 76 from the discharge opening 58, the discharge conduit 68 includes an enlarged, outlet chamber 86 provided with an outlet or outlet conduit 88 which communicates with the discharge opening 76 through the chamber 86 and is adapted to discharge the material from the apparatus. The shaft 70 carries a plurality of breaker elements 90 in the chamber 86, such breaker elements 90 serving during rotation of the shaft 70 to break-up compacted material discharged through the discharge opening 76 prior to the passage of the material through the outlet 88.

As illustrated in FIG. 1, an imperforate metering platform or dividing means 92 may be disposed transversely in the vessel 10 intermediate the upper and lower ends thereof to divide the interior of the vessel 10 into an upper or retention chamber 94 above the platform 92 and a lower or discharge chamber 96 below the platform 92, the platform 92 being mounted on the shaft 64 for conjoined driven rotation with the scraper 60. In this event, as will be noted, the inlets l8 and 22 will be connected to the retention chamber 94 and the latter will contain the beforedescribed, compacted material disintegrating and spreading means, while the discharge chamber 96 is provided with the discharge opening 58 and contains the rotating scraper 60. Also, as illustrated, the upper side of the platform 92 may be provided with an annular wall 98 downwardly sloping towards its periphery and adjacent such periphery spaced from the lower end of a depending annular wall 100 by an annular space 102 communicating the lower end of the retention chamber 94 with the upper end of the discharge chamber 96. This arrangement, as will be seen, causes the platform 92 to control the passage of material from the retention chamber 94 to the discharge chamber 96 and enables the rate of such material passage to be readily and simply varied by adjustment of the speed of the driven rotation of the platform 92. Hence, this arrangement is advantageously accompanied by control means controlling the speed of the driven rotation of the platform 92 responsive to the level of material in'the retention chamber 94, such control means being schematically depicted in FIG. 1 as including a conventional level sensing device 104 sensing the level of the material in the retention chamber 9 4 and connected to the motor 66 to cause the rotary speed at which the latterrotatably drives the platform 92 and the scraper 60 to be varied responsive thereto. Moreover, the wall 98 of the platform 92, as illustrated, may be provided with spiral flights 106 adapted to facilitate passage of material from the retention chamber 94 to the discharge chamber 96 through the space 102.

Throughout the operation of the beforedescribed apparatus, the driving motor 66 is continuously operated to provide continuous rotation of the shaft 64 and its carried scraper 60 and platform 92; and the driving motor 72 is also continuously operated to rotate the shaft 70 and the carried screw flight 78 and breaker elements 90. Similarly, the shaft 34 is continuously rotatably driven by its driving means (not shown) to cause continuous rotation of the feed and compacting screw 36; and the driving motor 28 is continuously operated to rotate the feed screw 24 and rotary pins 3 8. Pressurized fluid at constant, pre-determined pressure is maintained in the actuators 84 to cause the latter to exert pre-determined, equal forces yieldably biasing the flaps 80 against the discharge of material through the discharge opening 76, whereby the flaps yieldably restrain passage of material through the opening 76.

The gas or gaseous reagent (for example, chlorine gas or chlorine dioxide mixed with steam when the apparatus is employed for the bleaching of pulp) is continuously supplied to the vessel retention chamber 94 through the gas supply pipe 20 and gas inlet 18. The solid or solid-liquid material, such as lignocellulosic material, is continuously supplied through the supply conduit 30 to the rotatably driven feed and compacting screw 36 which compacts the material in the tapering portion 32 of the supply conduit 30, thereby forming a plug of the material upstream of the vessel to prevent the flow of undesirable gases to the vessel 10 through the supply conduit 30. The screws 24,36 feed this compacted material through the inlet 22 into the vessel retention chamber 94 whereupon the beforedescribed disintegrating and spreading means including the pins 38,40 disintegrates or breaks-up the compacted material and spreads the broken-up material across the cross-section of the retention chamber 94. This spread, disintegrated material falls downwardly in the retention chamber 94 to form a pile of the material on the wall 98 of the platform 92, the volume of which pile of material divided by the volumetric through-put of material through the apparatus determines the time the material is retained in the retention chamber 94 exposed to the gaseous reagent. The driven rotation of the platform 92 causes the latter to move material on the bottom of the pile outwardly to the periphery of the platform 92 where the material is'discharged through the annular opening 102 to the discharge chamber 96, the speed of the driven rotation of the platform 92 being controlled'responsive to the level 108 of the upper end of the pile of material. The material, thus discharged to the discharge chamber 96, falls downwardly therein by gravity.

The material at the bottom of the discharge chamber is raked along the bottom 56 of the vessel 10 towards the discharge opening 58 and discharged through the latter into the discharge conduit 68. The rotatably driven screw flight 78 conveys this discharged material through the discharge conduit 68 towards the discharge opening 76. The flaps 80, as beforedescribed, yieldably restrain the discharge of the material through the discharge opening 76 to thereby form a plug of the material at the opening 76 and cause the material to be discharged through the latter in compacted condition. This plug or compacted condition of the material, as will be seen, prevents the material passing through the opening 76 from including gas-containing interstices and thereby substantially minimizes the carry-over of gas with the material discharged through the opening 76. The chamber 86 receives the compacted material from the opening 76 and, after such material has been broken-up by the breaker elements 90, discharges the material through the apparatus outlet 88.

From the preceeding description, it will be seen that the material may be both supplied to the vessel 10 and discharged therefrom at consistences may be above l0 percent solid material. Also, the consistency of the discharged material may be, as desired or required, either higher or lower than, or the same as, that of the supp'lied material. Moreover, although the beforedescribed apparatus provides only for the supply of gas to the material in the vessel 10, it will be understood that liquids, steam and/or the like could also be supplied to the material in the vessel.

From the preceeding description, it will be seen that the invention provides new and improved means for attaining all of the beforestated objects and advantages. It will be understood, however, that, although only a single embodiment of the invention has been illustrated and hereinbefore described, the invention is not limited merely to this single embodiment, but rather contemplates other embodiments and variations within the scope of the following claims.

9 Having thus described our invention, we claim:

1. Apparatus for the gaseous reaction of material, comprising a vessel, means for supplying material to said vessel, said material supplying means including means for compacting material and supplying the material in compacted condition, means for breaking-up the compacted material and spreading the broken-up material in said vessel, means for supplying gas to said vessel, and discharge means for discharging material from said vessel, said discharge means including a discharge opening and flap means controlling the discharge of material through said discharge opening for causing the material to be discharged therethrough in compacted condition.

2. Apparatus according to claim 1, wherein said flap means extends generally transversely of said discharge opening and is movable to yieldably restrain discharge of material therethrough, and further comprising means for causing said flap means to yieldably restrain discharge of material through said discharge opening.

3. Apparatus according to claim 2, wherein said flap means is annular.

4. Apparatus according to claim 1, wherein said vessel is generally vertical, said material supplying means and said gas supplying means are connected to the upper end of said vessel, said compacted material breaking-up and spreading means is in the upper end of said vessel, and said discharge means is connected to the lower end of said vessel,

5. Apparatus according to claim 1, wherein said flap means includes a plurality of flaps extending generally transversely of said discharge opening and movable to yieldably restrain discharge of material therethrough, and further comprising means for causing said flaps to yieldably restrain discharge of material through said discharge opening.

6. Apparatus according to claim 5, wherein said flaps are pivotally mounted, and said yieldable restraining causing means comprises individual means for said flaps.

7. Apparatus according to claim 1, wherein said discharge means further includes conduit means, a second discharge opening communicating said conduit means with said vessel and connected through said conduit means to said discharge opening, rotatably driven screw means in said conduit means for conveying material from said second discharge opening towards said discharge opening, said flap means extending generally transversely of said discharge opening and being movable for varying the open area of said discharge opening, and means for yieldably biasing said flap means against discharge of material through said discharge opening.

8. Apparatus according to claim 7, wherein said flap means includes a plurality of flaps.

9. Apparatus according to claim 8, wherein said flaps are pivotally mounted, and said biasing means includes individual biasing means for said flaps.

10. Apparatus according to claim 8, wherein said screw means comprises support means and flight means on said support means, said conduit means includes an outlet opening on the opposite side of said discharge opening from said second discharge opening, said support means extends through said discharge opening, and further comprising means on said support means adjacent said outlet opening for breaking-up compacted material discharged through said discharge opening.

11. Apparatus according to claim 1, wherein said vessel is generally vertical, said material supplying means and said gas supplying means are connected to the upper end of said vessel, the lower end of said vessel is generally conical and provided with a second discharge opening offset from the center of said vessel, and further comprising rotatable scraper means in the lower end of said vessel movable over said second discharge opening, and conduit means communicating said second discharge opening with said discharge opening.

12. Apparatus according to claim 11, wherein said second discharge opening is elongated and longitudinally extends across substantially the width of said vessel at its offset location.

13. Apparatus according to claim 12, further comprising rotatably driven screw means in said conduit means for conveying material from said second discharge opening towards said discharge opening through said conduit means, said screw means comprising rotary support means and flight means carried by said support means, said flap means including a plurality of flaps extending generally transversely of said discharge opening and individually movable for yieldably restraining the discharge of material therethrough, and means for yieldably biasing said flaps against discharge of material through said discharge opening.

14. Apparatus according to claim 1, further comprising means in said vessel dividing said vessel into a retention chamber on one side of said dividing means and a communicating discharge chamber on the other side thereof, said dividing means controlling the passage of material from said retention chamber to said discharge chamber, said material supplying means and said gas supplying means being connected to said retention chamber, said discharge chamber being provided with a second discharge opening for discharging material therefrom, said compacted material breaking-up and spreading means being in said retention chamber, conduit means communicating said second discharge opening with said discharge opening, and scraper means in said discharge chamber.

15. Apparatus according to claim 14, wherein said vessel is generally vertical, and said retention and discharge chambers are, respectively, adjacent the upper and lower ends thereof.

16. Apparatus according to claim 15, wherein said dividing means is rotatably driven.

17. Apparatus according to claim 16, further comprising said second discharge opening being offset from the center of said vessel.

18. Apparatus according to claim 17, further comprising rotatably driven screw means in said conduit means for conveying material through said conduit means from said second discharge opening towards said discharge opening, said flap means comprising a plurality of flaps extending generally transversely of said discharge opening and movable for yieldably restraining discharge of material therethrough, and means for yieldably biasing said flaps against discharge of material through said discharge opening.

19. Apparatus according to claim 18, wherein said screw means includes rotary support means and flight means carried by said support means, said conduit means includes an outlet opening on the opposite side of said discharge opening from said second discharge opening, said support means extends through said discharge opening, and further comprising means carried by said support means adjacent said outlet opening for breaking-up the compacted material discharged through said discharge opening.

20. Apparatus according to claim 18, further comprising means for controlling the driven rotation of said dividing means responsive to the level of material in said retention chamber. 

1. Apparatus for the gaseous reaction of material, comprising a vessel, means for supplying material to said vessel, said material supplying means including means for compacting material and supplying the material in compacted condition, means for breaking-up the compacted material and spreading the broken-up material in said vessel, means for supplying gas to said vessel, and discharge means for discharging material from said vessel, said discharge means including a discharge opening and flap means controlling the discharge of material through said discharge opening for causing the material to be discharged therethrough in compacted condition.
 2. Apparatus according to claim 1, wherein said flap means extends generally transversely of said discharge opening and is movable to yieldably restrain discharge of material therethrough, and further comprising means for causing said flap means to yieldably restrain discharge of material through said discharge opening.
 3. Apparatus according to claim 2, wherein said flap means is annular.
 4. Apparatus according to claim 1, wherein said vessel is generally vertical, said material supplying means and said gas supplying means are connected to the upper end of said vessel, said compacted material breaking-up and spreading means is in the upper end of said vessel, and said discharge means is connected to the lower end of said vessel.
 5. Apparatus according to claim 1, wherein said flap means includes a plurality of flaps extending generally transversely of said discharge opening and movable to yieldably restrain discharge of material therethrough, and further comprising means for causing said flaps to yieldably restrain discharge of material through said discharge opening.
 6. Apparatus according to claim 5, wherein said flaps are pivotally mounted, and said yieldable restraining causing means comprises individual means for said flaps.
 7. Apparatus according to claim 1, wherein said discharge means further includes conduit means, a second discharge opening communicating said conduit means with said vessel and connected through said conduit means to said discharge opening, rotatably driven screw means in said conduit means for conveying material from said second discharge opening towards said discharge opening, said flap means extending generally transversely of said discharge opening and being movable for varying the open area of said discharge opening, and means for yieldably biasing said flap means against discharge of material through said discharge opening.
 8. Apparatus according to claim 7, wherein said flap means includes a plurality of flaps.
 9. Apparatus according to claim 8, wherein said flaps are pivotally mounted, and said biasing means includes individual biasing means for said flaps.
 10. Apparatus according to claim 8, wherein said screw means comprises support means and flight means on said support means, said conduit means includes an outlet opening on the opposite side of said discharge opening from said second Discharge opening, said support means extends through said discharge opening, and further comprising means on said support means adjacent said outlet opening for breaking-up compacted material discharged through said discharge opening.
 11. Apparatus according to claim 1, wherein said vessel is generally vertical, said material supplying means and said gas supplying means are connected to the upper end of said vessel, the lower end of said vessel is generally conical and provided with a second discharge opening offset from the center of said vessel, and further comprising rotatable scraper means in the lower end of said vessel movable over said second discharge opening, and conduit means communicating said second discharge opening with said discharge opening.
 12. Apparatus according to claim 11, wherein said second discharge opening is elongated and longitudinally extends across substantially the width of said vessel at its offset location.
 13. Apparatus according to claim 12, further comprising rotatably driven screw means in said conduit means for conveying material from said second discharge opening towards said discharge opening through said conduit means, said screw means comprising rotary support means and flight means carried by said support means, said flap means including a plurality of flaps extending generally transversely of said discharge opening and individually movable for yieldably restraining the discharge of material therethrough, and means for yieldably biasing said flaps against discharge of material through said discharge opening.
 14. Apparatus according to claim 1, further comprising means in said vessel dividing said vessel into a retention chamber on one side of said dividing means and a communicating discharge chamber on the other side thereof, said dividing means controlling the passage of material from said retention chamber to said discharge chamber, said material supplying means and said gas supplying means being connected to said retention chamber, said discharge chamber being provided with a second discharge opening for discharging material therefrom, said compacted material breaking-up and spreading means being in said retention chamber, conduit means communicating said second discharge opening with said discharge opening, and scraper means in said discharge chamber.
 15. Apparatus according to claim 14, wherein said vessel is generally vertical, and said retention and discharge chambers are, respectively, adjacent the upper and lower ends thereof.
 16. Apparatus according to claim 15, wherein said dividing means is rotatably driven.
 17. Apparatus according to claim 16, further comprising said second discharge opening being offset from the center of said vessel.
 18. Apparatus according to claim 17, further comprising rotatably driven screw means in said conduit means for conveying material through said conduit means from said second discharge opening towards said discharge opening, said flap means comprising a plurality of flaps extending generally transversely of said discharge opening and movable for yieldably restraining discharge of material therethrough, and means for yieldably biasing said flaps against discharge of material through said discharge opening.
 19. Apparatus according to claim 18, wherein said screw means includes rotary support means and flight means carried by said support means, said conduit means includes an outlet opening on the opposite side of said discharge opening from said second discharge opening, said support means extends through said discharge opening, and further comprising means carried by said support means adjacent said outlet opening for breaking-up the compacted material discharged through said discharge opening.
 20. Apparatus according to claim 18, further comprising means for controlling the driven rotation of said dividing means responsive to the level of material in said retention chamber. 